[libcxx-commits] [libcxx] r347399 - [libcxx] Mark stray symbols as hidden to try and fix the build

Tue Nov 27 10:35:21 PST 2018

Yes, we had a number of programs with a few very large stack frames, and
this setting (based on Louis' great work) solved that particular problem.

On Tue, Nov 27, 2018 at 10:02 AM Jordan Rupprecht <rupprecht at google.com>
wrote:

> I'm not really sure why; I was just the lucky build cop and started seeing
> failures in that area :)
>
> Fortunately Erik helped and suggested
> "_LIBCPP_HIDE_FROM_ABI_PER_TU_BY_DEFAULT:BOOL=ON" as a fix. The only
> context I can pull up is this:
> http://lists.llvm.org/pipermail/cfe-dev/2018-August/059156.html. Looks
> like we were hitting stack overflows without it.
>
> On Wed, Nov 21, 2018 at 9:34 AM Benjamin Kramer <benny.kra at gmail.com>
> wrote:
>
>> We are defining _LIBCPP_HIDE_FROM_ABI_PER_TU in our libc++ build. I don't
>> know why though.
>>
>> Jordan, do you remember why we need that flag?
>>
>> On Wed, Nov 21, 2018 at 6:30 PM Louis Dionne <ldionne at apple.com> wrote:
>>
>>> Thanks!
>>>
>>> The problem is, as the error says, that I did not apply the attribute to
>>> the first declaration of that operator+. I missed it because we have this
>>> frustrating habit of declaring and defining heavily templated functions
>>> separately.
>>>
>>> Also, how come are you using internal_linkage? Are you defining
>>> _LIBCPP_HIDE_FROM_ABI_PER_TU, and if so, why? Just trying to gather some
>>> user input.
>>>
>>> Louis
>>>
>>> On Nov 21, 2018, at 12:21, Benjamin Kramer <benny.kra at gmail.com> wrote:
>>>
>>> I'm still seeing things like
>>>
>>> In file included from llvm/projects/libcxx/src/ios.cpp:12:
>>> In file included from llvm/projects/libcxx/include/ios:216:
>>> In file included from llvm/projects/libcxx/include/__locale:15:
>>> llvm/projects/libcxx/include/string:4041:1: error: 'internal_linkage'
>>> attribute does not appear on the first declaration of 'operator+'
>>> operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const
>>> _CharT* __rhs)
>>> ^
>>> llvm/projects/libcxx/include/string:584:1: note: previous definition is
>>> here
>>> operator+(const basic_string<_CharT, _Traits, _Allocator>& __x, const
>>> _CharT* __y);
>>> ^
>>>
>>> Any idea what's going on?
>>>
>>> On Wed, Nov 21, 2018 at 6:03 PM Louis Dionne via libcxx-commits <
>>> libcxx-commits at lists.llvm.org> wrote:
>>>
>>>>
>>>>
>>>>
>>>> ---------- Forwarded message ----------
>>>> From: Louis Dionne <ldionne at apple.com>
>>>> To: libcxx-commits at lists.llvm.org
>>>> Cc:
>>>> Bcc:
>>>> Date: Wed, 21 Nov 2018 17:00:52 -0000
>>>> Subject: [libcxx] r347399 - [libcxx] Mark stray symbols as hidden to
>>>> try and fix the build
>>>> Author: ldionne
>>>> Date: Wed Nov 21 09:00:52 2018
>>>> New Revision: 347399
>>>>
>>>> URL: http://llvm.org/viewvc/llvm-project?rev=347399&view=rev
>>>> Log:
>>>> [libcxx] Mark stray symbols as hidden to try and fix the build
>>>>
>>>> r347395 changed the ABI list on Linux, but two of those symbols are
>>>> still
>>>> being exported from the shared object:
>>>>
>>>>     _ZSt18make_exception_ptrINSt3__112future_errorEESt13exception_ptrT_
>>>>
>>>> _ZNSt3__1plIcNS_11char_traitsIcEENS_9allocatorIcEEEENS_12basic_stringIT_T0_T1_EERKS9_PKS6_
>>>>
>>>> This commit makes sure those symbols are not exported, as they should
>>>> be.
>>>>
>>>> Modified:
>>>>     libcxx/trunk/include/exception
>>>>     libcxx/trunk/include/string
>>>>
>>>> Modified: libcxx/trunk/include/exception
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/exception?rev=347399&r1=347398&r2=347399&view=diff
>>>>
>>>> ==============================================================================
>>>> --- libcxx/trunk/include/exception (original)
>>>> +++ libcxx/trunk/include/exception Wed Nov 21 09:00:52 2018
>>>> @@ -164,7 +164,7 @@ public:
>>>>  };
>>>>
>>>>  template<class _Ep>
>>>> -exception_ptr
>>>> +_LIBCPP_INLINE_VISIBILITY exception_ptr
>>>>  make_exception_ptr(_Ep __e) _NOEXCEPT
>>>>  {
>>>>  #ifndef _LIBCPP_NO_EXCEPTIONS
>>>> @@ -223,7 +223,7 @@ _LIBCPP_NORETURN _LIBCPP_FUNC_VIS void r
>>>>  template <class _E> void *__GetExceptionInfo(_E);
>>>>
>>>>  template<class _Ep>
>>>> -exception_ptr
>>>> +_LIBCPP_INLINE_VISIBILITY exception_ptr
>>>>  make_exception_ptr(_Ep __e) _NOEXCEPT
>>>>  {
>>>>    return __copy_exception_ptr(_VSTD::addressof(__e),
>>>> __GetExceptionInfo(__e));
>>>>
>>>> Modified: libcxx/trunk/include/string
>>>> URL:
>>>> http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/string?rev=347399&r1=347398&r2=347399&view=diff
>>>>
>>>> ==============================================================================
>>>> --- libcxx/trunk/include/string (original)
>>>> +++ libcxx/trunk/include/string Wed Nov 21 09:00:52 2018
>>>> @@ -4036,7 +4036,7 @@ operator+(_CharT __lhs, const basic_stri
>>>>  }
>>>>
>>>>  template<class _CharT, class _Traits, class _Allocator>
>>>> -_LIBCPP_INLINE_VISIBILITY
>>>> +inline _LIBCPP_INLINE_VISIBILITY
>>>>  basic_string<_CharT, _Traits, _Allocator>
>>>>  operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
>>>> const _CharT* __rhs)
>>>>  {
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> ---------- Forwarded message ----------
>>>> From: Louis Dionne via libcxx-commits <libcxx-commits at lists.llvm.org>
>>>> To: libcxx-commits at lists.llvm.org
>>>> Cc:
>>>> Bcc:
>>>> Date: Wed, 21 Nov 2018 09:00:53 -0800 (PST)
>>>> Subject: [libcxx-commits] [libcxx] r347399 - [libcxx] Mark stray
>>>> symbols as hidden to try and fix the build
>>>> _______________________________________________
>>>> libcxx-commits mailing list
>>>> libcxx-commits at lists.llvm.org
>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/libcxx-commits
>>>
>>>
>>>
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